


hatch switch

by fannishcodex



Category: Star vs. The Forces Of Evil
Genre: Adopted Children, Adopted Sibling Relationship, Adoption, Age Swap, Alternate Universe, Alternate Universe - Canon Divergence, Alternate Universe - Siblings, Big Sisters, Brother-Sister Relationships, Gen, Protective Siblings, Siblings
Language: English
Status: In-Progress
Published: 2015-10-06
Updated: 2015-11-14
Packaged: 2018-04-25 02:00:27
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 3,627
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4942366
Author URL: https://archiveofourown.org/users/fannishcodex/pseuds/fannishcodex
Summary: <blockquote class="userstuff">
              <p>AU. Star Butterfly is not an only child.</p>
            </blockquote>





	1. part 1

**Author's Note:**

> Here's giftfic for editoress on an idea I've been meaning to do even before the Star Vs. the Forces of Evil season finale. So here's some originally pre-S1 finale SVtFoE AU fic.

"Your parents are  _so_  fun, Marco!" Star said in between bouncing on her new bed and chomping on her wand. "I had no idea parents could be that fun!"

"Uh huh, yeah," Marco slowly said, giving a weak chuckle as he watched his new housemate ascend and descend, wondering when the bed would give. "So, um...guessing your parents are pretty strict then?"

Star finally plopped down on the bed, blowing the hair out of her face. "Pretty sure I wouldn't be here if they weren't," the princess pointed out, though there was still a laugh in her voice. " _But_  it is way better than St. O's," and Star said this with a glance and beaming smile at Marco, that drew a reciprocal grin from the human.

"And, okay, my parents  _do_  have their moments, they're not always  _on_  all the time, you know what I mean?" Star said, looking back to the ceiling and spinning her wand. "Especially with my brother."

Marco pulled up a chair, flipping it around and sitting in it backwards. "So you're not an only child?"

"Nah, I have a baby brother, a real little monster," Star said, though her voice was completely fond, not irritated.

Marco gave a small chuckle. "Normally a pain, huh?" The human figured homesickness explained the difference in tone and content: Star's warm voice versus the less than flattering description of her sibling.

"Huh?" Star turned back around facing Marco, blinking. "What would make you think that?"

"Um, because you called him a real monster?" Marco was still smiling, amused.

Star tilted her head. "Because he  _is_  one." At Marco's blank stare, she continued, gesturing with her hands. "With the claws and the tail and cute little snout-he's adopted," Star finished, in response to Marco's growing confusion.

"Oh," Marco said. " _Oh_."

"Toffee's really sweet-"

"The candy?" Marco said, looking like someone who felt like he was being made fun of. "First we're talking about your brother, then candy-"

"Marco," and Star rolled her eyes, "Toffee's my brother's name and  _oh_  maybe  _that's_  why my parents named him that, because he was sweet even as a little baby hatchling-though his teething, man his  _teething_ , that was hardcore because he pretty much had all his fangs grown in and-"

Marco just sat back and listened to Star's animated stories about her family, still in a bit of a shock over the changes in his life and the ways his world had opened up.

###

Beyond Star's stories, her mirror was the first thing Marco had to really confirm Toffee's existence, just like he'd seen Star's mother in messages. (He hadn't seen Star's father yet.)

"-so boring around here now."

Marco had been heading to Star's room to see if she wanted to meet up with Alfonzo and Ferguson at the theater, when he heard that-a new voice, a small boy's.

"Ah, Toff, you just have to shake things up there yourself now," Star said, and Marco could see the back of her, bouncing on her toes. Then she seemed to deflate very slightly and run her hand through her hair. "Though not too much, you don't want to get into too much trouble-"

"Says the banished princess," said the mirror's image, which was that of a small reptilian creature, with dark feathers on his head, tied back into a small ponytail at the base of his neck. Small snout, claws, tail-like Star had said.

"I was sent away, not banished," Star insisted, her voice playfully high class. Her voice turned to normal when she asked, "Who said I was banished?"

"Overheard some trash in court-"

"Don't call them trash, Toff," Star said, and though her voice was easygoing, Marco's eyes widened. He never heard Star like that, like...really correcting someone else.

"They talk like trash," the small monster in the mirror grumbled, his yellow eyes glancing away from Star and glaring. "And you sound like Mom."

Marco saw Star cross her arms. "Okay, just gonna ignore that for now, I've got a better point to make." The princess raised her finger. "It's not forever you know, I'll be back home before you know it. And I'm sure mom and dad are gonna say any day now that you can come visit soon. And when you come to Earth, it'll be so cool, I'll show you-"

Toffee's skeptical look turned more eager as Star went on about the wonders of Earth they'd share soon, until he finally looked behind Star's back. "Is that Marco?" He asked, tilting his head.

Star immediately turned around, and Marco immediately felt like he'd been eavesdropping the whole time. "Sorry, I was just-"

"Oh Marco, I can finally introduce you two!" Star said, practically pouncing on Marco and dragging him over to the mirror phone.

"Toffee, this is my bestie on Earth, Marco-" Toffee gave Marco a little wave, which Marco returned. "-Marco, this is Toffee, my baby brother-"

"I'm eight," Toffee said.

"Exactly!" Star said, beaming, while Toffee rolled his eyes, and Marco thought, even from his perspective as an only child, that the small monster looked very much like a little brother.

###

Marco was concerned. Star had seemed a little anxious last night, and today that had increased. She seemed down and listless, except when trying to call Toffee up on her mirror.

"Hey Toff! ...Okay, you're not there, so just please call me back later when you can, I'm totally here to pick up...even if I'm not really there, at home, to...just call me back, okay? Okay. Love you."

Marco had heard Star continue to make messages like that.

She kept checking her mirror, and didn't really leave the room, in case the mirror should have a call. (Again it made Marco think of his late-night brainstorming sessions with Star about a portable mirror equivalent to an Earth cellphone, though nothing substantial had come of it.)

"What's up, Star? You seem...upset," Marco tried, feeling lame and useless. Maybe if he got her to share, talk.

Star paused her nervous chewing on her wand to stare at Marco. Then she resumed chewing her wand, looking away. Just when Marco was gonna try again, Star said, throwing her arms up and removing the wand from her mouth, "It's just, it's the thirty-seventh of G-"

Then she deflated, slumping further down her bed. "It's just some stupid Mewni holiday thing. First time I've been away from home for it."

Marco immediately frowned, feeling for his friend. "And you're missing out."

"I guess," Star mumbled, glaring fixedly on a pillow she tugged at.

"And your parents couldn't make an exception? Not even for a family holiday?"

Star blinked, then turned to Marco. "Family holiday?"

Something in Star's tone made Marco's response a little hesitant. Her voice had a slight bite to it. "I-isn't the Mewni holiday you're missing a time for family to gather around? Like Christmas?" He'd told Star about that, to her absolute fascination.

Star shook her head, impatient-over what, Marco wasn't sure. "No, Mewnipendance Day isn't like that, it's not nice like that, I thought it was, but it's not, it hasn't been for ages-"

The princess then sighed, though the look on her face was still stormy. She turned around in bed, back to Marco. "I'm sorry, it's...just complicated."

"Complicated?" Marco echoed, feeling even more out of sorts by Star's behavior. He'd never seen her this upset.

The little angry laugh she gave next wasn't reassuring. "Yeah, complicated. Doesn't help that mom and dad don't really talk about it, no one really talks about it, the stuff that-and I can't really tell Toffee  _anything_  when he asks me questions, and I'm his big sister, I should be able to answer his questions, but I just don't  _know_ -"

Star sighed, and Marco felt horrible, feeling like he'd made things worse, that he'd actually been prying and touched on a really sore, personal subject.

"Star, I'm sorry, I should've just kept my mouth sh-"

"Did you ever wonder, Marco?" Star suddenly asked.

When she didn't say anything more, Marco finally replied, "Wonder what?"

"Wonder why my parents adopted Toffee?"

"Wasn't really my place to ask-"

"Never thought it was weird?"

A small laugh actually slipped out of Marco. "No more weird than a princess from another dimension."

He'd hoped that would make Star face him with a smile. But she didn't move, her back still to him.

"D-do some people back on Mewni think it's...weird?" Marco asked, his voice softer.

"...Just some of the court, talking like trash," Star said, and Marco was unnerved by how small Star's voice sounded. "And-and y'know, Marco, I'm kinda tired, I'm just gonna try to take a nap now." Marco didn't even feel reassured when Star gave a very exaggerated yawn. "Mirror will probably wake me if there's a call, but if it doesn't, and you hear it, can you-"

"I'll wake you up if I hear the mirror ring." Marco promised. Finally Star turned around to give Marco a little smile, before turning her back on him again. Getting that response from Star didn't lighten Marco's mood like he had hoped.

###

Toffee saw the messages left by Star on his mirror.

"Um..."

There were a lot. The monster child clicked his mirror to idle mode, planning to look at his sister's messages tomorrow.


	2. part 2

**Summary for the Chapter:**

> Part 2: Star is six when her parents return and she gains a new brother.

**Notes for the Chapter:**

> A/N: Thanks for all the comments and encouragement! Here's the next part, jumping back to kid!Star POV on her parents adopting Toffee.
> 
> Disclaimer: I own nothing related to the Star Vs. the Forces of Evil.

Star is six, and her parents are coming home.

She bounces at the thought; everyone said they'd been fighting monsters, and she wants to ask what it was like for them. And she hadn't really seen them a lot even before they went off to fight, but maybe she'd see them more afterward.

Star wonders why the other grown-ups, her babysitter guards and servants, don't seem as happy as her. There's a lot of whispering and grumpy looks that Star pays some seconds to before growing bored and thinking of her parents again. She chews on one of her stuffed toys, wondering when they'll see her. She'd tried looking for them herself when she heard they were in the castle, but Nana Hail (the chief babysitter guard) wouldn't let her out of his sight. Unable to sneak off, she waits, light on her feet and bouncing and chewing on her toys.

Finally Papa picks Star up from her room. He sweeps her up in his arms, and his beard tickles her.

Papa tells Star that Mama is with her new little brother, and that they'll see them both now.

Papa has to explain. "Your mother and I adopted a baby. He'll be your little brother, making you his older sister. As his older sister, you have to love and look after him. He'll need you."

Star bounces in her father's arms and holds tight to his beard, while he carries her away. Papa further explains. "Your new brother is not a Mewman, but a monster—a baby one though. He's not like other monsters you've learned of. Understand?"

Star nods, accepting Papa's words, and asks what her new baby brother looks like, does he have tentacles or fur—

Papa tells her to wait and see.

Star is carried to her parents' room, and she makes grabby hands for Mama, standing by a blue bassinet. The queen takes her, holding her tight and planting a big wet kiss on her forehead. It makes Star giggle, and then she's climbing over Mama's shoulder, to look down at the bassinet.

"My new monster baby brother?"

"His name is Toffee, dear."

Star looks down, and large bright yellow eyes look up at her from the bassinet. They're set in a gray scaly face, above a short round upturned snout that's chewing on a blanket, with what looks like all his fangs grown in, but they're small and still slightly rounded at the tip. Star's eyes grow large, her mouth widens and rounds out, forming an  _oh_ ; she's seen babies before, and they were all lumpy and fat and round and tiny and cute, though they were all Mewni. This baby monster's cute and tiny, but slender and kinda scrawny, and Star is reminded of a tree sapling. But, he does have some roundness, in his snout and his head and the way his tail curves and a little bit with his belly and back, but he's not plump like she's seen other Mewni babies.

The baby monster's wearing warm red clothes, shirt and trousers that hang loosely. The clothes have an opening for his tail, which swishes softly in the other blankets not caught between his fangs. Star thought it was dark hair or fur on his head, but when she looks more closely, she realizes they're fluffy feathers. Star stretches down from her mother's arms, reaching for the feathers on Toffee's head.

"Star, be gentle," her mother warns.

"I wanna pet him!"

Mama's voice gains a familiar sternness. "He is not a pet, he is your brother."

"Ah, darling," Star hears Papa start, but she's focused entirely on reaching for Toffee, who just tilts his head at her and keeps chewing his blanket. "I don't believe Star means—well, I even described it as petting Star before, when she'd been Toffee's age, but I never meant she was—"

Star hears Mama sigh, sounding tired. Star thinks to clarify. "I just wanna touch Toffee's feathers."

"Of course, dear," her mother says, voice softening. "Again, just be gentle,  _don't_  pull. You don't want to hurt him by mistake. Babies are fragile. Soft. You can hurt them by accident if you're not careful, and they're not easy to heal."

The queen brings Star within reach of Toffee, and the princess pats her brother on the head three times, giggling as his head slightly bounces with each touch.

"Star," Mama warns, and the princess starts slowly running her fingers through Toffee's feathers instead.

The baby monster finally moves his head, and stretches it up more, his snout pressing against Star's fingers, sniffing at her.

It makes Star giggle; Toffee's scales and breath are nice and warm and soft.

"He's tickling me!"

Star then moves her hand away and tries stretching forward, tries sniffing Toffee in return. Now that she's closer, Toffee tries sniffing Star's hair, she can feel his little snout in her hair, it makes her giggle again.

When he gives a little cough, Star laughs, then kisses his snout.

"Silly little brother."

###

Star naturally thinks all happy-like, but she's feeling down. The six-year-old princess hasn't seen her parents as often as she thought she would get to once they returned. They're back to work like normal. Star's lessons haven't paused. And she doesn't even get to see Toffee that much.

Whenever she tries to see him by herself, grumpy-looking nannies force her out of the nursery. Star thought she proved she could be gentle with Toffee, but she guessed her parents hadn't told the nursery nannies, or they just couldn't believe it. And her own babysitter guards don't want to take her there. They seem actually spooked by Toffee.

"He's only a  _little_ monster," Star told them once, snickering. The thought of her babysitter guards, so big and tough, spooked by a small lizard monster with feathers for hair like her new brother—it was just really funny. "He's just a sweet baby."

"He won't always be one," one said, while another muttered, "It just wasn't  _natural_ ," and another begged for the princess' pardon. But they still wouldn't escort her to see Toffee in the nursery.

And sometimes—actually, weirdly often enough now, Star knows it's not always Mama-and-Papa-are-very-busy-working and Toffee's-in-the-nursery-with-the-sour-looking-nannies, but more and more it's Mama-and-Papa-keep-Toffee-around-while-working. The first time she saw them all together, Star was trying to sneak away from her tutors, and she found Mama and Papa talking with advisor people while Toffee napped in a nearby bassinet. Her tutors had caught up, and Star was forced to leave her parents and brother and return to her lessons.

Star tries to sneak away other times, sees them other times, her parents working while Toffee's nearby in his bassinet; or Mama holds him with one arm while her wand's in the other hand; or Papa carries him, and Toffee's either napping or chewing quietly on his blanket or sucking on his bottle.

Star knows it makes her jealous, her parents spending more time with Toffee. She's felt jealous before, when she realized Flying Princess Pony Head could always hover above the ground and she could not, no matter how hard she tried. But this jealousy feels bigger to Star, makes her eyes sting sometimes, makes her sometimes wish she could return her new baby brother to wherever he came from.

Star likes sneaking away in general, she still sneaks around the castle as a game even when she isn't trying to skip classwork. Star's heard grown-ups gossip this way, and even at fancy parties she sometimes has to go to and be very quiet at. Sometimes Star is right there, not even trying that hard to be sneaky, and grown-ups still talk, because either they still don't notice her right away because she's smaller than them, or they think she's not listening, that she won't really understand. And sometimes she's not listening, sometimes she doesn't understand; but sometimes she catches bits and pieces of their gossip. Normally Star either finds grown-up gossip boring or interesting, but lately it's been...weird. Like:

"It's a travesty—they pay more attention to that beast than their own daughter, our next queen."

"None of the nursemaids feel comfortable with that thing—they say it's unnaturally quiet, docile,  _watching_ , already has all its fangs grown in—their majesties  _have_  to give it more attention, if they're set on keeping it—"

"That'll be sorted out eventually, Queen Moon won't let that stand for long, bad work ethic that is—disobedience at worse—"

"But it's insanity what she's asking for though...simply not fair..."

"What's not fair is that a monster gets made  _prince_ —I work day in and day out in the kitchens, Mewman through and through, and some  _monster_  gets handpicked to live in the lap of luxury! Am I to  _bow_ to that wretch someday?!"

"Monster's just some war trophy for the Queen after those revolts, calling him 'prince' won't change that."

"Queen's just making an example of him."

"Sending a message to the monsters."

_Weird_  isn't the right word; it's mean, and it makes Star's stomach tie up in knots.

(Years later, Star will tell Marco she doesn't have answers when Toffee asks her all the  _why's_  about his adoption and Mewnipendence Day, and that's not exactly true; Star has inklings, theories, levels of gossip, half-formed ideas, all of them disturbing. Star knows her parents love Toffee. She knows it. But deep down she's not entirely sure that, for the very first time, when they took him in for the  _very_  first time...if it was out of love or something else, something colder. But nothing confirmed, no one will confirm, not her parents, anyone—gossip over Toffee would conflict a lot, too many different stories; gossip over Toffee had started to break down, Star's wondered forever if a royal gag order had been placed. And she wants to give Toffee the truth, not guesswork. Especially if the truth's serious; she doesn't want to make a mistake with this. And Marco is her bestie, but her bestie from  _Earth_ , and this is a Mewni thing, and Star's still not sure she can share everything with Marco. Not yet.)

###

"Can I sleep with you tonight?"

Star stands in her parents' doorway, watching Mama put down her hairbrush at her dressing table, and Papa look up from tickling Toffee, who's still giggling, tail wagging.

"Of course, darling," Papa says, and Star immediately dashes to their bed and jumps up. When she lands, making the bed bounce, she can hear Toffee's delighted laugh, and it makes her laugh too.

"Star, would you like to hold Toffee?" The king asks, and Star nods her head so fast, she feels slightly dizzy. Laughing, her father says, "All right. Be gentle."

"I was before!" Star pauses. "The very first time," she clarifies."

"Be gentle again. Always be gentle with Toffee, he's only a baby," Papa says. "Now, support his head; mind his tail."

"Uh huh," Star tells him. Papa gives her further instruction, carefully placing Toffee in her arms, showing her exactly where her hands should go. The baby monster purrs as this goes on, and the queen sits down on the bed with them.

"Mama, look, I'm holding Toff!" Star says, beaming, holding Toffee close and not seeming to notice him chewing on one of her ponytails.

"Yes sweetheart, I see," Mama says, smiling softly. "You're doing very well."

The queen gently tickles Toffee, making him laugh and release Star's ponytail. Mama sweeps that ponytail behind Star's shoulder, and does the same with the other one.

"I don't mind him chewing on my hair," Star says, enjoying the weight of her baby brother in her arms.

"I know, dear," Mama replies. Then she says, voice soft, "Babies need a lot of attention, Star. They're very young, and vulnerable, and need all the help they can get." Mama pauses. She seems to change her mind about something, and says, "We've been giving Toffee all the attention we can. You understand, don't you?"

Star thinks about it for a second, biting her lip. Then she nods. "Uh huh. And I'm a big girl."

"Yes, you are," the queen says, putting an arm around Star's shoulder. Papa ruffles her hair. Toffee tugs on the front of her dress, his little claws poking the fabric.

"We love you both equally," her mother promises. "No more, no less."

Star is six, and believes in her.

 

**Notes for the Chapter:**

> A/N: Thanks for reading, hope you enjoyed! Reviews/comments/feedback is always encouraged and appreciated. Next time should be jumping back to to a more present timeline/i.e. "Star Comes to Earth" time.

**Author's Note:**

> This was admittedly initially inspired by people saying there were physical/personality similarities between Loki and Toffee, and physical/personality similarities between between Thor and Star, and then my brainstorming for it just snowballed from there. Thanks for reading, hope you enjoyed! Feedback/comments/reviews are always appreciated and desired.


End file.
